It is possible by virtue of electrochemically or galvanically treating metal surfaces to oxidize, reduce, or etch said metal surfaces in a purposeful manner in conjunction with electrolyte solutions in order to change the characteristics of said metal surfaces.
It is possible by virtue of purposefully oxidizing the surface to achieve long-lasting colored regions on the surface. This method for providing an inscription and marking is mainly used on a small scale for inscribing small components.
A coating is applied as a special process of galvanic technology by means of the tampon-galvanic technique when marking metal surfaces; in particular the component that is to be coated is fixed at the minus pole or negative connection of a galvanic installation. The anode can be a plate that is encased by a wadding tampon or a rod that is embodied from a non-soluble material and is encased by a wadding tampon. The electrolyte solution can be supplied to this tool by way of a hose line; alternatively, the plate or the rod can be immersed together with the wadding tampon into an electrolyte bath.
The described electrochemical or galvanic process, in particular the tampon-galvanic process, can also be used inter alia on chromed surfaces and is used predominantly for cleaning, repairing coatings, for example a chrome layer, and also for inscribing or marking surfaces.
The long lasting colored inscriptions and/or markings on heavily stressed metal surfaces of round stock, for example on piston rods in fluid cylinders, such as for example hydraulic cylinders and/or pneumatic cylinders, can be provided in a conventional manner by laser beams, wherein in this case annealing colors are produced and/or material is removed from the surface of the round stock.
The thermal loading associated with laser treatment damages the material so that it is necessary to adopt expensive counter measures, for example in the form of special coatings on the components, in order to avoid excessive corrosion. Markings provided by laser treatment are also only partially resistant to mechanical loadings, in other words the surface of the round stock is only inadequately resistant to mechanical loadings. Long process times constitute a further disadvantage of laser treatment.